Human neutrophil chemotactic factor(abbreviated NCF hereinafter) is a physiologically active polypeptide, which plays an important role in developmental and homeostatic mechanism, such as migration (homing) of T lymphocytes to thymus and lymphonodes, and in the modulation of immuno responses. It has been reported that NCF has biological activities to attract neutrophils and lymphocytes, and to activate these cells (Yoshimura, T. et al., J. Immunol., 139, 788,1987; Walz, A. et al., Biochem. Biophys. Res. Commun., 149, 755, 1987; Gregory, H. et al., Biochem. Biophys. Res. Commun., 151, 833, 1988). These findings indicate that NCF is a useful immunotherapeutic agent for patients with malignant tumors and immunodeficiency diseases.
The present inventors have succeeded in the production of human NCF by recombinant DNA technology using E. coli as a host cell and also in the isolation of the said polypeptide from the soluble fraction of the transformanthomogenate, and a patent application on this invention was filed with the USPTO on May 2, 1988 as Ser. No. 189,164 now abandoned.